WASHINGTON, May 25, 2021 – Silver has been used for millennia for its antimicrobial and antibacterial properties. Although its use as a disinfectant is widely known, the effects of the interaction of silver with bacteria on silver itself are not well understood.
As antibiotic resistant bacteria become more and more prevalent, silver has seen strong growth in its use in things like antibacterial coatings. Yet the complex chain of events that lead to the eradication of bacteria is largely taken for granted, and a better understanding of this process may provide clues on how best to apply it.
In Chemical Physics Opinion, by AIP Publishing, researchers from Italy, the United States and Singapore studied the impacts of an interaction with bacteria on the structure of silver.
When monitoring the interaction of silver nanoparticles with a culture of E. Coli nearby, the researchers found that the silver was undergoing several dramatic changes. More particularly, the cells of E. Coli caused substantial changes in the size and shape of the silver particles.
It is often assumed that the money stays the same in this process, but the work done by the team shows that this is not true.
The electrostatic interaction between silver and bacteria causes some silver particles to dissolve by releasing ions that enter bacterial cells. This dissolution changes the shape of the silver particles, shrinking them and rounding them from triangular shapes to circles.
These effects are even more pronounced if the cells of E. Coli are pretreated with a molecule to increase the permeability of their membranes before they encounter silver.
“It appears from this study that money is ‘consumed’ from the interaction,” said Guglielmo Lanzani, one of the article’s authors and director of the Center for Nanotechnology and Technology. ‘IIT-Instituto di Tecnologia.
Fortunately, this “consumption” probably does not impact the antimicrobial properties of silver, because the effect is so weak.
“We believe that this does not affect the efficiency of the biocidal process and, due to the tiny mass exchange, the lifespan is essentially unlimited,” said Giuseppe Paternò, researcher at IIT and co-author of the ‘study. “The structural changes, however, affect the optical properties of metal nanostructures.”
Direct investigations into processes like these are difficult because laboratories are controlled environments that cannot fully grasp the complexities of a biological environment of bacterial cells.
Nevertheless, the group is considering further experiments to explore the chemical pathways that lead to structural changes in silver. They hope to find out why silver works better as an antibacterial surface than other materials, and why bacterial membranes are particularly vulnerable to silver, while other cells remain less affected.
The article “The impact of exposure to bacteria on the plasmon response of nanostructured silver surfaces” is written by Giuseppe Maria Paternò, Aaron Michael Ross, Silvia M. Pietralunga, Simone Normani, Nicholas Dalla Vedova, Jakkarin Limwongyut, Gaia Bondelli, Liliana Moscardi, Guillermo C. Bazan, Francesco Scotognella and Guglielmo Lanzani. The article will appear in Chemical physics opinion on May 25, 2021 (DOI: 10.1063 / 5.0042547). After this date, it can be consulted at https: /
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Chemical physics opinion publishes articles on important and emerging topics of interest to the chemical physics community. The journal focuses on experimental and theoretical research on fundamental questions of chemical physics and its applications in other branches of science, medicine and engineering. See https: /
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